on a recent job i did i used mapei DPM and was very impressed with it for lots of reasons. its premixed so you simply pour from container and roll evenly over the floor. what you dont use in the container you can put the lid back on and use at a later date. it was dry and ready to latex over after 2 hours !!! yes thats 2 hours !!! i have used to treadfast onecoat rapid dry DPM before but that took much longer to dry before i could latex over than this mapei product.
looks intresting, not a product i have used before. You say its pre mixed also? whats the max RH it can be used upto? Do you have a product code number?
Mapei EcoPrimPU1K Turbo is described as a onecomponent, moisture curing and rapid drying (40-50minutes) polyurethane surfacemembrane to waterproof and consolidate cementitious screeds. It is suitable for screeds not subject to rising damp butwith residual humidity higher thanBritish Standards 75% RH(BS8203) for laying resilient andwood flooring. EcoPrimPU1KTurbo is solvent–freewith exceptionally low emissions of volatile organic compounds.
Intresting. It sounds more like a dpm that you use before installing a wooden floor where the moister needs to be way lower than the 75%rh stated by British Standards. It dont tell you the max RH it can be used upto but it sounds like you can only use it on "dry" screed. (hence more suited for wooden floors) it states that the subfloor (screed) needs to be allowed to dry for 10 days for every Centremeter deep! Before you can apply the DPM. If thats the case the screed should be around about 75% rh moister content after that time frame has been allowed anyway so you wont need to apply a surface DPM unless installing wood flooring. So that will mean it cant be used on subfloors without a DPM or a Failed DPM also! Think i will give them a call and quiz them on this product before people start using it thinking it will do something it wont.
be interesting to see what you can find out. i sub contract off one local firm and its all they use nowadays.
I'm a DIY user, not a seasoned professional, so my opinion carries much less weight. But I've just put down a two-coat epoxy DPM supplied by Merlin Coatings, a less well-known manufacturer. I can't comment on its in-service performance as it's only just gone down, but it was good stuff to work with and went down very nicely. Some of the reasons why I chose Merlin are (not all of them applied in my particular situation, but I felt they were indicative of a technically advanced product): - Can be used down to 8 degrees C - Will cope with and suppress up to 99% relative humididty in the substrate - Can be applied to lightly contaminated surfaces (eg hydrocarbon staining) - Can be applied to wet surfaces (not applicable in my case, but impressive) - Good coverage rates (although I didn't quite achieve what was claimed) - Can be applied over underfloor heating (not applicable to me) - Excellent friendly and very accommodating technical and sales support - Good price - it's very competitively priced as you buy direct from the manufacturer Several of the above attributes are not shared by some other leading epoxy DPMs according to their own technical data. So either Merlin are making some very bold claims, or this is a very good product. I have no connection with Merlin Coatings, I'm just impressed enough to want to give them a mention here. There's more about the product on their website:
thanks for the info tigger. Epoxy 2 coat systems are all pretty much the same thing. However going over wet wont work. However it may be that the wording is not the best and they mean wet screed as below 99% rh. However 99% rh is really pushing it also. Most say 97-98 rh max. Sounds like a good product tho if the price is right.
I would never try to stick anything to wet concrete myself if I could possibly help it. Intuitively it just isn't going to work. But this is what the Merlin product tech sheet says: "Barrier Coat can be applied directly onto wet surfaces free from standing water". So they're really asking for trouble unless there's some truth in their claim. As you say epoxy DPMs are all essentially the same thing, but I guess they play around with the exact recipe (viscosity, cure rate, solids content etc) to achieve slightly different performance. I know a lot about polyester resins, but little about epoxy other than that it's basically the work of the devil! But there does appear to be something that you can to to epoxies to make them perform better in wet conditions - JB Weld, for example, isn't recommended for use in the wet, but JB Marine is (this could just be marketing though!) Dom
on reading again = "free from standing water" they mean you cant go onto water basically, but wet as in moister content being above 75%RH (british standard) . So anything below 99% in other words. However i would like to see a max of 98% as 99% really is pushing very close to 100% = water !
Mat, I think we're pretty much saying the same thing. But a 60mm fresh laid sand/cement screed (for example) would look pretty dry after only a few days if not cured under polythene - it's quite likely there would be no dark damp patches showing on the surface. However, inside its mass it would still have very high moisture - 97% plus RH I reckon. Merlin seem to claim that you could lay their barrier coat over a surface that is actually as wet as it could be without having pools of water on the surface - ie presumably it could be 'glistening' wet but with no puddles. Mind you I think you'd be daft to try this! Dom
I've always used a 2 part epoxy in the past, But tried creom on last job, following Matts recommendation. ( so if it fails Matt... I'll be calling you!! :lol: ) Its certainly a lot easier to work with and no waste like epoxy, so its a lot better value.
Product Size Price (+vat) Merlin Barrier Coat 5kg unit £55 Merlin Barrier Coat 25kg unit £255 twice the price of pallmans uzin pe 400 which is a 1 part quick curing 2hrs.
I normally use F75 or F76, never tried creom. might give it a bash. always get waste with 75 and 76. :evil:
I have been playing with a new product over the last couple of days and so far i think its the best DPM system i have used so far. Im still to set up some moister tests with it at the college to see how far the product can be pushed and what sort of moister reading we get. I will let you all know next week. Anyway the product is Mapie 1K Turbo DPM. it is like creom where you can put the lid back on and use another day.
